Going to stereo output while keeping mono capability, any ideas?

That kinda looks like it would be somewhat of a big-Ol'hairdo to wire .
Also consider that stock humbucking "P" pick-ups are spun in two directions so one pickup
Would be pushing the speaker out the other would be pulling the speaker in .
Might want to consider using pick-ups spun the same and with the same magnetic Polarities .

 

One half of a split-coil pickup is reverse-wound, reverse-polarity from the other. When wired correctly it will not be out of phase, but if you lower the volume of one half of it you will defeat the hum-canceling benefit of having a split-coil pickup.
Here's a RIC schematic to peruse:

http://www.rickenbacker.com/pdfs/19557.pdf

 

Not really sure how the Ric and Billy Sheehan basses are wired .
But if your running two signals with two amps of the same . you would want the
Phase to be the same .

 

I might be able to make some pickups, not sure when. Kinda need the practice and kinda want to try
A new material combination so not sure how they would sound.

 

Wow,
How to over complicate the most simple and useful design.

A P pickup is a split pickup, not two front and back pickups. They are wired together to hum cancel. If you separate them out stereo you will lose that and what you will gain is the ability to mess up the signal between the EA and DG strings.

Only do what you’re planning if you actually have two pickups and something to gain. Also, your scheme looks very ugly and isn’t functional: too easy to brush those forward knobs. A stereo arrangement would be better with one stereo jack. No need for a switch: the jack is switchable for a stereo or mono cable. Stacked volume/tone would save some space and get you down to two shafts. I’m sure KBD could help with a wiring scheme.

 

It can be done. I've made a stereo P bass out of a copy years ago. You get a persistent background hum from plugging into two amps simultaneously, and each pickup half senses a wee bit of the strings of the other half as well.

Going into 'solution looking for a problem' territory.

 

What I'm wondering is this: Why stereo split the P pickup? Why not add a bridge pickup and wire the neck and the bridge pickup to stereo? That's something I'm planning for my next build. But maybe I'm not seeing what you're trying to do here.

 

This is an awful idea IF you are planning on using two halves of a traditional P bass pickup. Awful.

If you want that kind of control, get something designed for it.

Ubertar Hexaphonic Guitar Pickups - One and Two String Pickups for guitar and bass

Or go this route with an actual different pickup for each string and wire the EA and DG pickups together.


BUT, keep in mind that magnetic fields aren't THAT directional. You'll get bleed from on string to the next anyway. It's not as though the magnets on your pickups are "pointed" straight up at the strings. I personally never understood the whole adjustable pole pieces thing. I have noticed tremendous differences adjusting the height of whole pickups. I have maxed out the adjustable poles on my DiMarzio pickup and never noticed a difference in sound from string to string.

By trying to use a standard P pickup to pull it off, you're trying to jam a square peg into a round hole.

 

Stereo split-strings wiring has been around for many years. IIRC, I think I first saw it in Adrian Legg's book published back in the early 80's.

As others have said, each will hum on their own, but I say go for it. If you've got two amps, this could be pretty fun to mess around with. Especially with pog pedals etc around these days.

Here's how to wire it....


Personally, I'd use stacked pots, and a stereo jack, so that the bass looks pretty standard, and functions normally with a regular mono lead, using the top knobs. It also means you don't have to route under the 'guard.

 

Along these lines of a split-signal. I have a fretless Epiphone Zenith that has a magnetic pickup at the base of the fretboard (NanoMag) and a piezo at the bridge (NanoFlex). They are wired to dual output jacks (somewhat visible in the pic).

One output jack is mono - for both pickups. The other is stereo - for the NanoFLex. Plugging into the stereo jack (NanoFLex) converts the mono jack to stereo (NanoMag only). TBH - I've never actually plugged into both jacks - just seems unnecessarily complicated.

Controlwise - there are stacked bass and treble knobs, a common volume knob and a blend knob. Oddly, I tend to keep the blend knob 100% NanoFlex/piezo.

It is a beautiful bass with a wonderful sound. Here's a pic:

 

Might help to paint the sides of the bobbin with nickel paint to redirect the magnetic field ?
If your phase of both pick-ups are the same I dont see an issue with strings bleeding through .

 

Wiring aside, what exactly are you trying to achieve? Do you have specific use(s) in mind, or just experimenting?

If you want to process highs and lows separately, you want two pickups (not two halves of a split p), spaced on the bass to give you two sounds. Like PJ, or a P with a neck pickup (Sheehan style). I personally found the PJ route didn’t work well in stereo, but never tried the Sheehan arrangement. I found that duplicating the P signal later in the chain (with a Boss LS2 or similar pedal) worked better for what I wanted. Mind you, I don’t think you can passively “duplicate” the signal from one pickup (in this case, standard P) by wiring it to a stereo output.

But if you indeed want to split the sound from E and A strings from the sound on D and G strings, you can do that passively, like you described. However, I’m not sure I see this being a useful mod? I guess it would allow you, for example, to play a clean bass line on EA side, and a dirty/processed melodic line on the DG side. Or play octaves with different processing on either side, maybe simulate a disco synth line

So depending on what you want to achieve, your scheme might work or not work.

 

Yep. That bass has only one pickup.

 

P-type pickup is only one pickup, it just looks like two, so you can't.

 

I think this is the crux of the confusion.

Terminology is important. What do we mean when we say "pickup"? To me a pickup is a "device which converts mechanical string energy into electrical energy, and spans all strings". By that definition a P-bass has one pickup.

If you're looking to add a second P pickup elsewhere on the bass, and you want one of them to go to one amp and another to go to another amp, that's fairly straightforward, and can be done easily using a switched jack - the switched jack lets you have automatic mono/stereo switching when using one or two cables. This Switchcraft jack would work: Switchcraft : Product Summary

If, as others have interpreted, you want to send the E and A strings to one amp while sending the D and G strings to another amp, well, that's also possible, but of dubious benefit. In that case you'll want to wire the two halves of the single pickup independently, still using a switched jack.

 

A split-coil pickup is actually two halves of a pickup combined to make one.
Since it has two coils, it is split-able. Heck, it's in the name, split-coil.